db_index

[t,r] = db_index(D, cl, C, p, q)

 DB_INDEX Davies-Bouldin clustering evaluation index.

 [t,r] = db_index(D, cl, C, p, q)

  Input and output arguments ([]'s are optional):  
    D     (matrix) data (n x dim)
          (struct) map or data struct
    cl    (vector) cluster numbers corresponding to data samples (n x 1)
    [C]   (matrix) prototype vectors (c x dim) (default = cluster means)
    [p]   (scalar) norm used in the computation (default == 2)
    [q]   (scalar) moment used to calculate cluster dispersions (default = 2)
 
    t     (scalar) Davies-Bouldin index for the clustering (=mean(r))
    r     (vector) maximum DB index for each cluster (size c x 1)    
 
 See also  KMEANS, KMEANS_CLUSTERS, SOM_GAPINDEX.